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Johan KorsnesJiri Kosina
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HID: core: fix off-by-one memset in hid_report_raw_event()
In case a report is greater than HID_MAX_BUFFER_SIZE, it is truncated, but the report-number byte is not correctly handled. This results in a off-by-one in the following memset, causing a kernel Oops and ensuing system crash. Note: With commit 8ec321e ("HID: Fix slab-out-of-bounds read in hid_field_extract") I no longer hit the kernel Oops as we instead fail "controlled" at probe if there is a report too long in the HID report-descriptor. hid_report_raw_event() is an exported symbol, so presumabely we cannot always rely on this being the case. Fixes: 966922f ("HID: fix a crash in hid_report_raw_event() function.") Signed-off-by: Johan Korsnes <jkorsnes@cisco.com> Cc: Armando Visconti <armando.visconti@st.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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Lines changed: 3 additions & 1 deletion

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drivers/hid/hid-core.c

Lines changed: 3 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1741,7 +1741,9 @@ int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, u32 size,
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rsize = ((report->size - 1) >> 3) + 1;
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if (rsize > HID_MAX_BUFFER_SIZE)
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if (report_enum->numbered && rsize >= HID_MAX_BUFFER_SIZE)
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rsize = HID_MAX_BUFFER_SIZE - 1;
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else if (rsize > HID_MAX_BUFFER_SIZE)
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rsize = HID_MAX_BUFFER_SIZE;
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if (csize < rsize) {

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